Merging upstream version 1.66.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

9 files changed, 185 insertions, 67 deletions

diff --git a/src/tools/rust-analyzer/crates/hir/Cargo.toml b/src/tools/rust-analyzer/crates/hir/Cargo.toml
index 8e6a2441b..e1418de3c 100644
--- a/src/tools/rust-analyzer/crates/hir/Cargo.toml
+++ b/src/tools/rust-analyzer/crates/hir/Cargo.toml
@@ -13,9 +13,9 @@ doctest = false
 rustc-hash = "1.1.0"
 either = "1.7.0"
 arrayvec = "0.7.2"
-itertools = "0.10.3"
-smallvec = "1.9.0"
-once_cell = "1.12.0"
+itertools = "0.10.5"
+smallvec = "1.10.0"
+once_cell = "1.15.0"
 
 stdx = { path = "../stdx", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
diff --git a/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs b/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs
index 5edc16d8b..c5dc60f1e 100644
--- a/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs
@@ -1,7 +1,7 @@
 //! Re-export diagnostics such that clients of `hir` don't have to depend on
 //! low-level crates.
 //!
-//! This probably isn't the best way to do this -- ideally, diagnistics should
+//! This probably isn't the best way to do this -- ideally, diagnostics should
 //! be expressed in terms of hir types themselves.
 use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
diff --git a/src/tools/rust-analyzer/crates/hir/src/display.rs b/src/tools/rust-analyzer/crates/hir/src/display.rs
index 0e29c52ad..27b2f445d 100644
--- a/src/tools/rust-analyzer/crates/hir/src/display.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/display.rs
@@ -492,6 +492,9 @@ impl HirDisplay for TypeAlias {
         write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
         let data = f.db.type_alias_data(self.id);
         write!(f, "type {}", data.name)?;
+        let def_id = GenericDefId::TypeAliasId(self.id);
+        write_generic_params(def_id, f)?;
+        write_where_clause(def_id, f)?;
         if !data.bounds.is_empty() {
             f.write_str(": ")?;
             f.write_joined(&data.bounds, " + ")?;
diff --git a/src/tools/rust-analyzer/crates/hir/src/from_id.rs b/src/tools/rust-analyzer/crates/hir/src/from_id.rs
index 9c7558d19..f825a72c0 100644
--- a/src/tools/rust-analyzer/crates/hir/src/from_id.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/from_id.rs
@@ -140,6 +140,7 @@ impl From<DefWithBody> for DefWithBodyId {
             DefWithBody::Function(it) => DefWithBodyId::FunctionId(it.id),
             DefWithBody::Static(it) => DefWithBodyId::StaticId(it.id),
             DefWithBody::Const(it) => DefWithBodyId::ConstId(it.id),
+            DefWithBody::Variant(it) => DefWithBodyId::VariantId(it.into()),
         }
     }
 }
@@ -150,6 +151,7 @@ impl From<DefWithBodyId> for DefWithBody {
             DefWithBodyId::FunctionId(it) => DefWithBody::Function(it.into()),
             DefWithBodyId::StaticId(it) => DefWithBody::Static(it.into()),
             DefWithBodyId::ConstId(it) => DefWithBody::Const(it.into()),
+            DefWithBodyId::VariantId(it) => DefWithBody::Variant(it.into()),
         }
     }
 }
@@ -172,9 +174,7 @@ impl From<GenericDef> for GenericDefId {
             GenericDef::Trait(it) => GenericDefId::TraitId(it.id),
             GenericDef::TypeAlias(it) => GenericDefId::TypeAliasId(it.id),
             GenericDef::Impl(it) => GenericDefId::ImplId(it.id),
-            GenericDef::Variant(it) => {
-                GenericDefId::EnumVariantId(EnumVariantId { parent: it.parent.id, local_id: it.id })
-            }
+            GenericDef::Variant(it) => GenericDefId::EnumVariantId(it.into()),
             GenericDef::Const(it) => GenericDefId::ConstId(it.id),
         }
     }
@@ -188,9 +188,7 @@ impl From<GenericDefId> for GenericDef {
             GenericDefId::TraitId(it) => GenericDef::Trait(it.into()),
             GenericDefId::TypeAliasId(it) => GenericDef::TypeAlias(it.into()),
             GenericDefId::ImplId(it) => GenericDef::Impl(it.into()),
-            GenericDefId::EnumVariantId(it) => {
-                GenericDef::Variant(Variant { parent: it.parent.into(), id: it.local_id })
-            }
+            GenericDefId::EnumVariantId(it) => GenericDef::Variant(it.into()),
             GenericDefId::ConstId(it) => GenericDef::Const(it.into()),
         }
     }
diff --git a/src/tools/rust-analyzer/crates/hir/src/lib.rs b/src/tools/rust-analyzer/crates/hir/src/lib.rs
index e4bb63a86..f5324208c 100644
--- a/src/tools/rust-analyzer/crates/hir/src/lib.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/lib.rs
@@ -39,7 +39,7 @@ use arrayvec::ArrayVec;
 use base_db::{CrateDisplayName, CrateId, CrateOrigin, Edition, FileId, ProcMacroKind};
 use either::Either;
 use hir_def::{
-    adt::{ReprKind, VariantData},
+    adt::{ReprData, VariantData},
     body::{BodyDiagnostic, SyntheticSyntax},
     expr::{BindingAnnotation, LabelId, Pat, PatId},
     generics::{TypeOrConstParamData, TypeParamProvenance},
@@ -50,7 +50,7 @@ use hir_def::{
     resolver::{HasResolver, Resolver},
     src::HasSource as _,
     AdtId, AssocItemId, AssocItemLoc, AttrDefId, ConstId, ConstParamId, DefWithBodyId, EnumId,
-    FunctionId, GenericDefId, HasModule, ImplId, ItemContainerId, LifetimeParamId,
+    EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId, ItemContainerId, LifetimeParamId,
     LocalEnumVariantId, LocalFieldId, Lookup, MacroExpander, MacroId, ModuleId, StaticId, StructId,
     TraitId, TypeAliasId, TypeOrConstParamId, TypeParamId, UnionId,
 };
@@ -61,12 +61,10 @@ use hir_ty::{
     diagnostics::BodyValidationDiagnostic,
     method_resolution::{self, TyFingerprint},
     primitive::UintTy,
-    subst_prefix,
     traits::FnTrait,
-    AliasEq, AliasTy, BoundVar, CallableDefId, CallableSig, Canonical, CanonicalVarKinds, Cast,
-    ClosureId, DebruijnIndex, GenericArgData, InEnvironment, Interner, ParamKind,
-    QuantifiedWhereClause, Scalar, Solution, Substitution, TraitEnvironment, TraitRefExt, Ty,
-    TyBuilder, TyDefId, TyExt, TyKind, TyVariableKind, WhereClause,
+    AliasTy, CallableDefId, CallableSig, Canonical, CanonicalVarKinds, Cast, ClosureId,
+    GenericArgData, Interner, ParamKind, QuantifiedWhereClause, Scalar, Substitution,
+    TraitEnvironment, TraitRefExt, Ty, TyBuilder, TyDefId, TyExt, TyKind, WhereClause,
 };
 use itertools::Itertools;
 use nameres::diagnostics::DefDiagnosticKind;
@@ -74,7 +72,7 @@ use once_cell::unsync::Lazy;
 use rustc_hash::FxHashSet;
 use stdx::{impl_from, never};
 use syntax::{
-    ast::{self, HasAttrs as _, HasDocComments, HasName},
+    ast::{self, Expr, HasAttrs as _, HasDocComments, HasName},
     AstNode, AstPtr, SmolStr, SyntaxNodePtr, TextRange, T,
 };
 
@@ -349,7 +347,10 @@ impl ModuleDef {
             ModuleDef::Module(it) => it.id.into(),
             ModuleDef::Const(it) => it.id.into(),
             ModuleDef::Static(it) => it.id.into(),
-            _ => return Vec::new(),
+            ModuleDef::Variant(it) => {
+                EnumVariantId { parent: it.parent.into(), local_id: it.id }.into()
+            }
+            ModuleDef::BuiltinType(_) | ModuleDef::Macro(_) => return Vec::new(),
         };
 
         let module = match self.module(db) {
@@ -378,10 +379,10 @@ impl ModuleDef {
             ModuleDef::Function(it) => Some(it.into()),
             ModuleDef::Const(it) => Some(it.into()),
             ModuleDef::Static(it) => Some(it.into()),
+            ModuleDef::Variant(it) => Some(it.into()),
 
             ModuleDef::Module(_)
             | ModuleDef::Adt(_)
-            | ModuleDef::Variant(_)
             | ModuleDef::Trait(_)
             | ModuleDef::TypeAlias(_)
             | ModuleDef::Macro(_)
@@ -538,6 +539,30 @@ impl Module {
                     }
                     acc.extend(decl.diagnostics(db))
                 }
+                ModuleDef::Adt(adt) => {
+                    match adt {
+                        Adt::Struct(s) => {
+                            for diag in db.struct_data_with_diagnostics(s.id).1.iter() {
+                                emit_def_diagnostic(db, acc, diag);
+                            }
+                        }
+                        Adt::Union(u) => {
+                            for diag in db.union_data_with_diagnostics(u.id).1.iter() {
+                                emit_def_diagnostic(db, acc, diag);
+                            }
+                        }
+                        Adt::Enum(e) => {
+                            for v in e.variants(db) {
+                                acc.extend(ModuleDef::Variant(v).diagnostics(db));
+                            }
+
+                            for diag in db.enum_data_with_diagnostics(e.id).1.iter() {
+                                emit_def_diagnostic(db, acc, diag);
+                            }
+                        }
+                    }
+                    acc.extend(decl.diagnostics(db))
+                }
                 _ => acc.extend(decl.diagnostics(db)),
             }
         }
@@ -582,8 +607,13 @@ impl Module {
 
     /// Finds a path that can be used to refer to the given item from within
     /// this module, if possible.
-    pub fn find_use_path(self, db: &dyn DefDatabase, item: impl Into<ItemInNs>) -> Option<ModPath> {
-        hir_def::find_path::find_path(db, item.into().into(), self.into())
+    pub fn find_use_path(
+        self,
+        db: &dyn DefDatabase,
+        item: impl Into<ItemInNs>,
+        prefer_no_std: bool,
+    ) -> Option<ModPath> {
+        hir_def::find_path::find_path(db, item.into().into(), self.into(), prefer_no_std)
     }
 
     /// Finds a path that can be used to refer to the given item from within
@@ -593,8 +623,15 @@ impl Module {
         db: &dyn DefDatabase,
         item: impl Into<ItemInNs>,
         prefix_kind: PrefixKind,
+        prefer_no_std: bool,
     ) -> Option<ModPath> {
-        hir_def::find_path::find_path_prefixed(db, item.into().into(), self.into(), prefix_kind)
+        hir_def::find_path::find_path_prefixed(
+            db,
+            item.into().into(),
+            self.into(),
+            prefix_kind,
+            prefer_no_std,
+        )
     }
 }
 
@@ -863,7 +900,7 @@ impl Struct {
         Type::from_def(db, self.id)
     }
 
-    pub fn repr(self, db: &dyn HirDatabase) -> Option<ReprKind> {
+    pub fn repr(self, db: &dyn HirDatabase) -> Option<ReprData> {
         db.struct_data(self.id).repr.clone()
     }
 
@@ -941,6 +978,21 @@ impl Enum {
     pub fn ty(self, db: &dyn HirDatabase) -> Type {
         Type::from_def(db, self.id)
     }
+
+    /// The type of the enum variant bodies.
+    pub fn variant_body_ty(self, db: &dyn HirDatabase) -> Type {
+        Type::new_for_crate(
+            self.id.lookup(db.upcast()).container.krate(),
+            TyBuilder::builtin(match db.enum_data(self.id).variant_body_type() {
+                Either::Left(builtin) => hir_def::builtin_type::BuiltinType::Int(builtin),
+                Either::Right(builtin) => hir_def::builtin_type::BuiltinType::Uint(builtin),
+            }),
+        )
+    }
+
+    pub fn is_data_carrying(self, db: &dyn HirDatabase) -> bool {
+        self.variants(db).iter().any(|v| !matches!(v.kind(db), StructKind::Unit))
+    }
 }
 
 impl HasVisibility for Enum {
@@ -949,6 +1001,12 @@ impl HasVisibility for Enum {
     }
 }
 
+impl From<&Variant> for DefWithBodyId {
+    fn from(&v: &Variant) -> Self {
+        DefWithBodyId::VariantId(v.into())
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Variant {
     pub(crate) parent: Enum,
@@ -983,6 +1041,14 @@ impl Variant {
     pub(crate) fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
         db.enum_data(self.parent.id).variants[self.id].variant_data.clone()
     }
+
+    pub fn value(self, db: &dyn HirDatabase) -> Option<Expr> {
+        self.source(db)?.value.expr()
+    }
+
+    pub fn eval(self, db: &dyn HirDatabase) -> Result<ComputedExpr, ConstEvalError> {
+        db.const_eval_variant(self.into())
+    }
 }
 
 /// Variants inherit visibility from the parent enum.
@@ -1023,7 +1089,7 @@ impl Adt {
     pub fn ty_with_args(self, db: &dyn HirDatabase, args: &[Type]) -> Type {
         let id = AdtId::from(self);
         let mut it = args.iter().map(|t| t.ty.clone());
-        let ty = TyBuilder::def_ty(db, id.into())
+        let ty = TyBuilder::def_ty(db, id.into(), None)
             .fill(|x| {
                 let r = it.next().unwrap_or_else(|| TyKind::Error.intern(Interner));
                 match x {
@@ -1118,8 +1184,9 @@ pub enum DefWithBody {
     Function(Function),
     Static(Static),
     Const(Const),
+    Variant(Variant),
 }
-impl_from!(Function, Const, Static for DefWithBody);
+impl_from!(Function, Const, Static, Variant for DefWithBody);
 
 impl DefWithBody {
     pub fn module(self, db: &dyn HirDatabase) -> Module {
@@ -1127,6 +1194,7 @@ impl DefWithBody {
             DefWithBody::Const(c) => c.module(db),
             DefWithBody::Function(f) => f.module(db),
             DefWithBody::Static(s) => s.module(db),
+            DefWithBody::Variant(v) => v.module(db),
         }
     }
 
@@ -1135,6 +1203,7 @@ impl DefWithBody {
             DefWithBody::Function(f) => Some(f.name(db)),
             DefWithBody::Static(s) => Some(s.name(db)),
             DefWithBody::Const(c) => c.name(db),
+            DefWithBody::Variant(v) => Some(v.name(db)),
         }
     }
 
@@ -1144,6 +1213,7 @@ impl DefWithBody {
             DefWithBody::Function(it) => it.ret_type(db),
             DefWithBody::Static(it) => it.ty(db),
             DefWithBody::Const(it) => it.ty(db),
+            DefWithBody::Variant(it) => it.parent.variant_body_ty(db),
         }
     }
 
@@ -1152,6 +1222,7 @@ impl DefWithBody {
             DefWithBody::Function(it) => it.id.into(),
             DefWithBody::Static(it) => it.id.into(),
             DefWithBody::Const(it) => it.id.into(),
+            DefWithBody::Variant(it) => it.into(),
         }
     }
 
@@ -1368,6 +1439,7 @@ impl DefWithBody {
             DefWithBody::Function(it) => it.into(),
             DefWithBody::Static(it) => it.into(),
             DefWithBody::Const(it) => it.into(),
+            DefWithBody::Variant(it) => it.into(),
         };
         for diag in hir_ty::diagnostics::incorrect_case(db, krate, def.into()) {
             acc.push(diag.into())
@@ -2474,7 +2546,7 @@ impl TypeParam {
         let resolver = self.id.parent().resolver(db.upcast());
         let ty = params.get(local_idx)?.clone();
         let subst = TyBuilder::placeholder_subst(db, self.id.parent());
-        let ty = ty.substitute(Interner, &subst_prefix(&subst, local_idx));
+        let ty = ty.substitute(Interner, &subst);
         match ty.data(Interner) {
             GenericArgData::Ty(x) => Some(Type::new_with_resolver_inner(db, &resolver, x.clone())),
             _ => None,
@@ -2728,7 +2800,22 @@ impl Type {
     }
 
     fn from_def(db: &dyn HirDatabase, def: impl HasResolver + Into<TyDefId>) -> Type {
-        let ty = TyBuilder::def_ty(db, def.into()).fill_with_unknown().build();
+        let ty_def = def.into();
+        let parent_subst = match ty_def {
+            TyDefId::TypeAliasId(id) => match id.lookup(db.upcast()).container {
+                ItemContainerId::TraitId(id) => {
+                    let subst = TyBuilder::subst_for_def(db, id, None).fill_with_unknown().build();
+                    Some(subst)
+                }
+                ItemContainerId::ImplId(id) => {
+                    let subst = TyBuilder::subst_for_def(db, id, None).fill_with_unknown().build();
+                    Some(subst)
+                }
+                _ => None,
+            },
+            _ => None,
+        };
+        let ty = TyBuilder::def_ty(db, ty_def, parent_subst).fill_with_unknown().build();
         Type::new(db, def, ty)
     }
 
@@ -2868,7 +2955,11 @@ impl Type {
         alias: TypeAlias,
     ) -> Option<Type> {
         let mut args = args.iter();
-        let projection = TyBuilder::assoc_type_projection(db, alias.id)
+        let trait_id = match alias.id.lookup(db.upcast()).container {
+            ItemContainerId::TraitId(id) => id,
+            _ => unreachable!("non assoc type alias reached in normalize_trait_assoc_type()"),
+        };
+        let parent_subst = TyBuilder::subst_for_def(db, trait_id, None)
             .push(self.ty.clone())
             .fill(|x| {
                 // FIXME: this code is not covered in tests.
@@ -2880,27 +2971,14 @@ impl Type {
                 }
             })
             .build();
-        let goal = hir_ty::make_canonical(
-            InEnvironment::new(
-                &self.env.env,
-                AliasEq {
-                    alias: AliasTy::Projection(projection),
-                    ty: TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0))
-                        .intern(Interner),
-                }
-                .cast(Interner),
-            ),
-            [TyVariableKind::General].into_iter(),
-        );
+        // FIXME: We don't handle GATs yet.
+        let projection = TyBuilder::assoc_type_projection(db, alias.id, Some(parent_subst)).build();
 
-        match db.trait_solve(self.env.krate, goal)? {
-            Solution::Unique(s) => s
-                .value
-                .subst
-                .as_slice(Interner)
-                .first()
-                .map(|ty| self.derived(ty.assert_ty_ref(Interner).clone())),
-            Solution::Ambig(_) => None,
+        let ty = db.normalize_projection(projection, self.env.clone());
+        if ty.is_unknown() {
+            None
+        } else {
+            Some(self.derived(ty))
         }
     }
 
@@ -2944,7 +3022,7 @@ impl Type {
 
         let adt = adt_id.into();
         match adt {
-            Adt::Struct(s) => matches!(s.repr(db), Some(ReprKind::Packed)),
+            Adt::Struct(s) => matches!(s.repr(db), Some(ReprData { packed: true, .. })),
             _ => false,
         }
     }
diff --git a/src/tools/rust-analyzer/crates/hir/src/semantics.rs b/src/tools/rust-analyzer/crates/hir/src/semantics.rs
index 416b6f580..119ec3210 100644
--- a/src/tools/rust-analyzer/crates/hir/src/semantics.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/semantics.rs
@@ -257,6 +257,11 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
     pub fn original_ast_node<N: AstNode>(&self, node: N) -> Option<N> {
         self.imp.original_ast_node(node)
     }
+    /// Attempts to map the node out of macro expanded files.
+    /// This only work for attribute expansions, as other ones do not have nodes as input.
+    pub fn original_syntax_node(&self, node: &SyntaxNode) -> Option<SyntaxNode> {
+        self.imp.original_syntax_node(node)
+    }
 
     pub fn diagnostics_display_range(&self, diagnostics: InFile<SyntaxNodePtr>) -> FileRange {
         self.imp.diagnostics_display_range(diagnostics)
@@ -956,6 +961,16 @@ impl<'db> SemanticsImpl<'db> {
         )
     }
 
+    fn original_syntax_node(&self, node: &SyntaxNode) -> Option<SyntaxNode> {
+        let InFile { file_id, .. } = self.find_file(node);
+        InFile::new(file_id, node).original_syntax_node(self.db.upcast()).map(
+            |InFile { file_id, value }| {
+                self.cache(find_root(&value), file_id);
+                value
+            },
+        )
+    }
+
     fn diagnostics_display_range(&self, src: InFile<SyntaxNodePtr>) -> FileRange {
         let root = self.parse_or_expand(src.file_id).unwrap();
         let node = src.map(|it| it.to_node(&root));
diff --git a/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs b/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs
index ba9a1cfb6..fa45e3c12 100644
--- a/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs
@@ -115,7 +115,7 @@ pub(super) struct SourceToDefCtx<'a, 'b> {
 }
 
 impl SourceToDefCtx<'_, '_> {
-    pub(super) fn file_to_def(&mut self, file: FileId) -> SmallVec<[ModuleId; 1]> {
+    pub(super) fn file_to_def(&self, file: FileId) -> SmallVec<[ModuleId; 1]> {
         let _p = profile::span("SourceBinder::to_module_def");
         let mut mods = SmallVec::new();
         for &crate_id in self.db.relevant_crates(file).iter() {
@@ -130,7 +130,7 @@ impl SourceToDefCtx<'_, '_> {
         mods
     }
 
-    pub(super) fn module_to_def(&mut self, src: InFile<ast::Module>) -> Option<ModuleId> {
+    pub(super) fn module_to_def(&self, src: InFile<ast::Module>) -> Option<ModuleId> {
         let _p = profile::span("module_to_def");
         let parent_declaration = src
             .syntax()
@@ -151,7 +151,7 @@ impl SourceToDefCtx<'_, '_> {
         Some(def_map.module_id(child_id))
     }
 
-    pub(super) fn source_file_to_def(&mut self, src: InFile<ast::SourceFile>) -> Option<ModuleId> {
+    pub(super) fn source_file_to_def(&self, src: InFile<ast::SourceFile>) -> Option<ModuleId> {
         let _p = profile::span("source_file_to_def");
         let file_id = src.file_id.original_file(self.db.upcast());
         self.file_to_def(file_id).get(0).copied()
@@ -384,7 +384,7 @@ impl SourceToDefCtx<'_, '_> {
         } else {
             let it = ast::Variant::cast(container.value)?;
             let def = self.enum_variant_to_def(InFile::new(container.file_id, it))?;
-            VariantId::from(def).into()
+            DefWithBodyId::from(def).into()
         };
         Some(cont)
     }
diff --git a/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs b/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs
index 342912b67..07bae2b38 100644
--- a/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs
@@ -22,7 +22,7 @@ use hir_def::{
     resolver::{resolver_for_scope, Resolver, TypeNs, ValueNs},
     type_ref::Mutability,
     AsMacroCall, AssocItemId, DefWithBodyId, FieldId, FunctionId, ItemContainerId, LocalFieldId,
-    Lookup, ModuleDefId, VariantId,
+    Lookup, ModuleDefId, TraitId, VariantId,
 };
 use hir_expand::{
     builtin_fn_macro::BuiltinFnLikeExpander,
@@ -302,10 +302,15 @@ impl SourceAnalyzer {
             }
         }
 
+        let future_trait = db
+            .lang_item(self.resolver.krate(), hir_expand::name![future_trait].to_smol_str())?
+            .as_trait()?;
         let poll_fn = db
             .lang_item(self.resolver.krate(), hir_expand::name![poll].to_smol_str())?
             .as_function()?;
-        let substs = hir_ty::TyBuilder::subst_for_def(db, poll_fn).push(ty.clone()).build();
+        // HACK: subst for `poll()` coincides with that for `Future` because `poll()` itself
+        // doesn't have any generic parameters, so we skip building another subst for `poll()`.
+        let substs = hir_ty::TyBuilder::subst_for_def(db, future_trait, None).push(ty).build();
         Some(self.resolve_impl_method_or_trait_def(db, poll_fn, &substs))
     }
 
@@ -321,8 +326,10 @@ impl SourceAnalyzer {
         };
         let ty = self.ty_of_expr(db, &prefix_expr.expr()?.into())?;
 
-        let op_fn = self.lang_trait_fn(db, &lang_item_name, &lang_item_name)?;
-        let substs = hir_ty::TyBuilder::subst_for_def(db, op_fn).push(ty.clone()).build();
+        let (op_trait, op_fn) = self.lang_trait_fn(db, &lang_item_name, &lang_item_name)?;
+        // HACK: subst for all methods coincides with that for their trait because the methods
+        // don't have any generic parameters, so we skip building another subst for the methods.
+        let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None).push(ty.clone()).build();
 
         Some(self.resolve_impl_method_or_trait_def(db, op_fn, &substs))
     }
@@ -337,8 +344,10 @@ impl SourceAnalyzer {
 
         let lang_item_name = name![index];
 
-        let op_fn = self.lang_trait_fn(db, &lang_item_name, &lang_item_name)?;
-        let substs = hir_ty::TyBuilder::subst_for_def(db, op_fn)
+        let (op_trait, op_fn) = self.lang_trait_fn(db, &lang_item_name, &lang_item_name)?;
+        // HACK: subst for all methods coincides with that for their trait because the methods
+        // don't have any generic parameters, so we skip building another subst for the methods.
+        let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None)
             .push(base_ty.clone())
             .push(index_ty.clone())
             .build();
@@ -354,10 +363,14 @@ impl SourceAnalyzer {
         let lhs = self.ty_of_expr(db, &binop_expr.lhs()?.into())?;
         let rhs = self.ty_of_expr(db, &binop_expr.rhs()?.into())?;
 
-        let op_fn = lang_names_for_bin_op(op)
+        let (op_trait, op_fn) = lang_names_for_bin_op(op)
             .and_then(|(name, lang_item)| self.lang_trait_fn(db, &lang_item, &name))?;
-        let substs =
-            hir_ty::TyBuilder::subst_for_def(db, op_fn).push(lhs.clone()).push(rhs.clone()).build();
+        // HACK: subst for `index()` coincides with that for `Index` because `index()` itself
+        // doesn't have any generic parameters, so we skip building another subst for `index()`.
+        let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None)
+            .push(lhs.clone())
+            .push(rhs.clone())
+            .build();
 
         Some(self.resolve_impl_method_or_trait_def(db, op_fn, &substs))
     }
@@ -371,7 +384,13 @@ impl SourceAnalyzer {
 
         let op_fn =
             db.lang_item(self.resolver.krate(), name![branch].to_smol_str())?.as_function()?;
-        let substs = hir_ty::TyBuilder::subst_for_def(db, op_fn).push(ty.clone()).build();
+        let op_trait = match op_fn.lookup(db.upcast()).container {
+            ItemContainerId::TraitId(id) => id,
+            _ => return None,
+        };
+        // HACK: subst for `branch()` coincides with that for `Try` because `branch()` itself
+        // doesn't have any generic parameters, so we skip building another subst for `branch()`.
+        let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None).push(ty.clone()).build();
 
         Some(self.resolve_impl_method_or_trait_def(db, op_fn, &substs))
     }
@@ -799,9 +818,10 @@ impl SourceAnalyzer {
         db: &dyn HirDatabase,
         lang_trait: &Name,
         method_name: &Name,
-    ) -> Option<FunctionId> {
-        db.trait_data(db.lang_item(self.resolver.krate(), lang_trait.to_smol_str())?.as_trait()?)
-            .method_by_name(method_name)
+    ) -> Option<(TraitId, FunctionId)> {
+        let trait_id = db.lang_item(self.resolver.krate(), lang_trait.to_smol_str())?.as_trait()?;
+        let fn_id = db.trait_data(trait_id).method_by_name(method_name)?;
+        Some((trait_id, fn_id))
     }
 
     fn ty_of_expr(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<&Ty> {
diff --git a/src/tools/rust-analyzer/crates/hir/src/symbols.rs b/src/tools/rust-analyzer/crates/hir/src/symbols.rs
index 616a406c7..fd78decda 100644
--- a/src/tools/rust-analyzer/crates/hir/src/symbols.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/symbols.rs
@@ -244,6 +244,10 @@ impl<'a> SymbolCollector<'a> {
             DefWithBodyId::ConstId(id) => Some(
                 id.lookup(self.db.upcast()).source(self.db.upcast()).value.name()?.text().into(),
             ),
+            DefWithBodyId::VariantId(id) => Some({
+                let db = self.db.upcast();
+                id.parent.lookup(db).source(db).value.name()?.text().into()
+            }),
         }
     }